Abrading tool



l. J. SNADER ABRADING TOOL May 30, 1944.

Filed July 28, 1941 lll ITNRM Q //////l Patented May 30, 1944 ABRADING 'rooL Ira J. Snader, Detroit,'Mich., assignor to Ex- Cell-O Corporation, Detroit, Mich., a corporation of Michigan Application July 28, 1941, Serial No. 404,290

8 Claims.

The invention relates generally to abrading or lapping tools or the like for removing material by an abrading action from the surfaces of cylindrical bores.

More speciilcally, the invention is particularly applicable to an abrading tool which embodies' a mandrel having tapering or wedge surfaces for effecting radial adjustment of abrading devices arranged to coact with said surfaces, and in which the abrading devices are arranged to present in any position of adjustment active abrading surfaces that are substantially segments of a cylinder and have dat supporting faces related to the axis of the cylindrical segments on an acute angle complemental to the angle of the tapering mandrei surfaces.

The primary object of the` present invention' is to provide a novel abrading tool of the foregoing character in which the abrading devices are positively connected with the mandrel by snugly interiitting parts effective to permit longitudinal adjustment along the tapering surfaces and at the same time to restrain the devices from leaving thesurfaces in response to centrifugal force.

Other objects and advantages will become apparent from the following description and in the accompanying drawing, in which:

Figure 1 is an axial sectional view through an abrading tool embodying the features of the invention.

Figs. 2 and 3 are end and transverse sectional views of the tool respectively as indicated by the lines 2-2 and 3 3 of Fig. 1.

Fig, 4 is a perspective view looking toward the iiat face of an abrasive element forming part of each device.

Fig. 5 is a perspective view looking toward the top of a holder forming part of each abrading device.

Fig. 6 is a perspective view looking toward the:

bottom of the holder.

modifications and alternative constructions, I

have shown inthe drawing and will herein describe in detail the preferred embodiment, but it to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

The abrading tool,`which embodies the features of the present invention, comprises the mandrel I2 and the abrading devices I3 (two of which are herein shown) associated with the mandrel for quick assembly, accurate adjustment, and efiicient operation.

The mandrel I2 in the preferred form shown in Figs. 1 and 7 is an elongated circular rod having a head I4 rigidly secured to its inner end. The outer end has oppositely disposed tapering wedge surfaces I5 which slope gently and unlformly to a relatively thin end I6 located on-a diameter of the mandrel. An upstanding rib Il extends longitudinally andsubstantially medially from the end edge of each. tapering surface l5.V The ribs on both surfaces are alike and are of uniform width and height. The ribs extend a substantial distance along the tapered surfaces, and `beyond each rib and in longitudinal alinement therewith, the shank of the mandrel is grooved as at I8 approximately to the head It. It `will be understood that the mandrel I2 is adapted tobe mounted in, and connected through the head It for rotary drive by, a supporting member, such as a tool spindle (not shown).

Each abrading device I3 includes an abrading element l I9 (see Fig. 4) having an active face 2l of sectional cylindrical contour. Oppositethe active face 20 is a fiat face 2l defined preferably by the plane of a chord of the cylinder which is angularly related to the axis of the cylindrical surface at an acute angle complemental to the angle of a tapering mandrel surface I5. The resulting body of the abrading element I9 is somewhat shorter than the ribs I'I on the mandrel I5, and is shaped as a secantial segment of a cylinder tapering gradually and uniformly from end to end both in width and thickness. The active face 20 of the body is formed on a radius slightly greater than that of the mandrel. The width of the fiat face 2l at the larger end is preferably only slightly less than the diameter of the cylinder. It is to be understood that the abrading element may be made of any suitable material, such for example as ineiy divided bonded abrasive.

The abrading element Isis preferably mounted on a supporting member 22 constituting a holder or shoe to complete the abrading device I3. As illustrated in Figs. 5 and 6, one preferred form of is to be understood that I do not thereby intend holder 22 comprises a iiat plate somewhat longer than the abrading element I9 and shaped to `taper uniformly from one end to the other in accordance with the taper of the dat face 2| of the abrading element. The varying width dimensions of the plate are slightly less than those of corresponding parts of the abrading element race 2| so that when the element and plate are appropriately secured together, as by adhesive, in face to face abutment with the wider dimensions substantially coinciding, the side margins of the abrading element will extend slightly beyond or overhang the margins of the plate (see Figs. 2

and 3). Thus, only the active face of the abradflat face 2l of the element I9. In a die casting,

the pins 24 may be formed integral with the plate 22, and located on the longitudinal center line. The plate 22 is also formed in the inner face 26 with suitable means slidably interlocking with the rib I'I onl the mating wedge surface I5 of the mandrel I2. To this end, the rib I'I is formed as a dovetailed guide, and the plate is formed with a longitudinal medial dovetailed guideway 21 slidably intertting therewith. The relationship permits endwise movement of the abrading device I3 on the mandrel I2, but presents lateral separation in=all positions of the adjustment and affords a positive rotary driving connection between the parts. The plane of the holder 22, when as- `of the holder 22.

abrading devices I3 are positively held against the wedge surfaces i5.

In the modified form illustrated in Figs. 8, 9 and 10. the holder 22* consists of a sheet metal plate of which the medial longitudinal portion has been oil'set to one side to form a dovetailed guide groove Iii'l adapted to interfit for relative longitudinal adjustment with the rib I1 on one of the wedge surfaces I5l of the mandrel |23. The offset portion defines a longitudinal medial upstanding rib or projection 30 on the opposed side The abrading element IS!a is formed in the at face 2 I* with a' longitudinal medial groove 3| of uniform width and height throughout its length and having parallel sides to receive the rib30. Thus, the rib 30 and groove 3| serve the same function in this form as do the pins 24 and recesses 25 in the first form. In other respects the construction is similar to that shown in Figs. 1 to 7, and the corresponding parts are identied by the same reference numerals plus the latter a,

In the second modified form of Fig. 10, the mandrel I2b is formed along each wedge surface I5b with a longitudinal medial rib 32 of T-shape in transverse form. The holder 22b is formed in one side with a longitudinal medial T-slot 33 slidably engaging vwith the rib 32.- In other respects the construction is similar to that shown in Figs. 1 to 7, and the corresponding parts are, therefore, identified by the reference numerals v plus the letter "b.

sembled with the abrading element is, has the same angular relationship to the active cylindrical face 2l and to a tapering mandrel surface I5`as does the flat face 2| of the element. As may be seen in Figs. 2 and 3, the lateral dimension of the tapering mandrel surfaces I5 is narrower than the width of the fiat faces 2| on the abrading elements I9.

A control and adjusting element is arranged to extend endwise from the narrower end of the plate 22 substantially as a continuation of the .central section thereof. In this instance, the element consists of a.thin elongated rod or wire 23 suitably secured at one end to the narrow end por- 'tion of the plate. The wire is dimensioned to seat relatively snugly in the related mandrel groove Il, and the free end thereof is bent to provide a right angular end portion 23 adaptedr t0 be anchored against endwise movement in the mandrel support.

In operation and assuming that the abrading devices I3 are assembled with the mandrel I2, and that the mandrel and the control elements 23 are connected to a suitable supporting and driving means, as shown for example in application Serial No. 264,706, filed March 29, 1939, by

- Paul R. Giertsen. and issued as Patent No. 2,268,-

479 on Dec. 23, 1941, the abrading devices are adjusted to a minimum diameter or a sumciently reduced diameter to enter the bore of the work to be lapped. The mandrel I2 is rotated. and, as the working operation continues. longitudinal adjustment of, the mandrel vrelative to the control elements 23 is effected to increase the cutting diameter of the tool assembly progressively to the desired finished work size. During the rotation of the mandrel I2, either in or out of the work, the

It is to be noted that all three forms of the invention provide for interlocking slidable engagement between the mandrel and the holder to permit relative longitudinal adjustment while preventing transaxial separation, and provide means for locating the holder and the abrading element in predetermined relation. By reason of the foregoing construction, the tool is readily adjustable and at the same time the abrading elements are held against lateral separation regardless of whether the tool is in or out of the work. Consequently, the tool can be rotated at high speeds, and can be conveniently inserted into the work.

I claim as my invention:

1. A holder for the abrading element of an abrading tool comprising an elongated flat plate formed in one side with an intermediate longitudinally extending dovetail groove and pro' vided on the other side with a plurality of longitudinally spaced upstandingl projections adapted to intert with the abrading element.

2. A holder for the abrading element of an abrading tool comprising a flat elongated plate formed in one side with a longitudinal medial groove having at least one undercut side and formed on the other side with two upstanding loeating pins spaced longitudinally on the medial center line.

3. An abrading element for an abrading tool comprising a body shaped as a secantial segment of a cylinder. the plane of the secant cord being angular with respect to the axis of curvature of the cylindrical surface to provide a body of tapering width, the large end of said body being substantially at, and the plane face of said body being formed with at least two longitudinally spaced recesses.

4. An abrading device for an abrading tool comprising, in combination, an elongated plate tapering in Width from one end to the other end and having a longitudinal medial dovetail groove in one side, an abrading element having an elongated body. shaped as a secantial segment of a cylinder with the plane of the secant cord located at an acute angle to the axis of the cylindrlcal surface whereby the body has a gently ta- 'pering form, the iiat face of said body being secured to the other side of said plate. and locating means interconnecting said plate and said element, said locating means consisting ot two 1ongitudinally spaced pins on said plate projecting into recesses in the flat face of said element.

5.V|A holder forl the abrading element of an abrading tool comprising an elongated ilat plate formed in one side with an intermediate longitudinally extending T s1ot constituting a groove with undercut sides and provided on the other side with a plurality of longitudinally spaced upstanding projections adapted to intert with the abrading element.

6. An abrading device for an abrading tool comprising, in combination, an elongated nat plate formed in one side with an intermediate longitudinally extending dovetail groove and on the other side with a plurality of longitudinally spaced upstanding projections, and an abrading element having a body shaped as a secantial segment of a cylinder, theplane of the secant cord being angular with respect to the axis of curvature of the cylindrical surface to provide a body of tapering width, the large end of said body being substantially nat, and the plane face of said body being formed with a plurality o1 longitution to said plate, the longitudinal edges of said element extending beyond the corresponding margins of said plate.

7. An abrading element for an abrading tool comprising a body shaped as a secantlal segment of a cylinder, the plane of the secant cord being angular with respect to the axis o; curvature of the cylindrical surface to provide a body oi tapering width, the large end of said body being substantially nat, and the plane face of said body being formed with two longitudinally spaced holes located near opposite ends on the longitudinal medial center line of said face.

8. An abrading tool comprising, in combination, a mandrel consisting of an elongated rod having a longitudinally inclined wedge surface formed with a longitudinally intermediate dovetail guide rib, a holder consisting of a flat plate having a dovetail groove in one side slidably engaging said rib and provided on the other side with a plurality of longitudinally spaced upstanding projections, and an abrading element having an elongated body shaped as. a secantial segment dinally spaced recesses interntting with said pro# iections to locate said element in deiinite relaot a cylinder with the plane of the secant cord located at an acute angle to the axis of the cy- 'liudrical surface whereby the body has a gently tapering form, the nat face of said body being formed with a plurality of longitudinally spaced recesses intertting with said projections to locate said element in definite relation to Said plate.

IRA. J. SNADER. 

